Rectifier



April 18, 1933. 1,904,334

S. 5. SMITH RECTIFIER Filed March 29, 1930 2 Sheets-Sheet l W K? 1 n.F15 1 v I z April 18, 1933.

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Patented Apr. 18, 1933 UNITED Arum oFricEg SYDNEY S. SMITH, OF TULSA,OKLAHOMA, ASSIGNOR TO SHELL PETROLEUM CORPORATION, A CORPORATION OFVIRGINIA RECTIFIER Application filed March 29, 1930. Serial No. 439,883.

This invention'relates to the art of distillation and more particularlyto apparatus for fractionally distilling by rectification compositeliquids comprising components having diiferent boiling points.

The embodiment of the invention particularly described is adapted forthe rectification of hydrocarbon mixtures such as natural gas gasolineor refinery gas condensates, but

it should be understood that the process has wider uses and is notlimited, therefore, to refining of petroleum products.

A more specific object of the invention is to provide apparatus foreffecting a sharp cut between the fractions of a liquid which includesvolatile fractions having difierent boiling points, whereby a separationof the various fractions may be made, and selected products withdrawn insubstantially a pure state.

The general object of the invention is to provide apparatus forcontinuous fractional distillation of volatile liquids which is,accurate, eflicient, economical in operation and simple to control.

Fig. 1 is a side view of the apparatus partly diagrammatical.

Fig. 2 is a detail drawing partly in section of the upper part of theapparatus in- Icluding the condenser.

Fig. 3 is a detail view partly in section of the lower part of theapparatus'including the kettle.

Fig. 4 is a cross-section through either the condenser or the kettle online H, Fig.

2, or Fig. 3.

,Fig. 5 is a detail view of a plate showing the core construction.

Fig. 6 is a cross-section through a plate 40 on line 6-6, Fig. 5. 1

The apparatus comprises generally a series of horizontal cylindricalplates arranged in a vertical plane; a kettle at the bottom; a condenserat the top; a number of series of vertical connections between thekettle,

plates and condenser, each series of connections being arranged in avertical line and arranged to permit from any section of a platedownward flow only in the liquid phase, and horizontal and upward flowin the vapor phase; means for introducing the input on a series ofplates at one end; means for withdrawing the liquid component at thebottom, the final end vapor component at the top, and intermediatecomponents in the vapor phase at intermediate plates, the withdrawaltaking place at the end opposite the end receiving the input; and meansfor automatically regulating the temperatures by controlling the flow ofthe heating fluid 0 through the kettle and the cooling fluid through thecondenser.

The plate assembly comprises a series of condenser plates 1 in the formof cylindrical tubes each horizontally disposed and arranged in avertical plane and equally spaced one from the other. The kettle 2 ismounted at the bottom and a condenser 3 is mounted at the top of theplate assembly. The ketnumber of series of vertical tubes 4:, each ofthe tubes in a series being in vertical alignment. The tubes trmay beattached to the plates 1, the kettle 2 and the condenser? by welding.

The left end of the apparatus may for convenience be designated thereceiving side and the right end the delivery side.

Each of the plates 1 has at the receiving side a reducer head 6 in whichmay be fitted a plug 7 or a valve 8. On the delivery side it may beprovided with a valve 9 for withdrawal of a component in the vapor phaseeither for purpose of sampling, or condensation and storage. Each plate1 has a core in order to increase the contact surface and such a coremay be constructed of a tight I roll of expanded metal lath 11 wrappedwith connection 19. A connection 20 is provided 7 23 providing chambers24 and 25. A con- Q-Bmay comprise a pipe 41 leading from a plate nection26 is made with the chamber 24 for the introduction of a. cooling fluidsuch as water and a connection 27 is made with the chamber 25 for thewithdrawal of the spent fluid. A connection 28 is made with the shell 21for the withdrawal of the final end vapor component and a manuallycontrolled valve 29 may be interposed in a pipe leading from theconnection 28 for the control of the flow of the end vapor component. Asafety pressure valve 30 in communication with the con- -nection 28 maybe ordinarily used for the discharge of the vapor component.

A manifold 32 is connected to a series of plates 1 through the valves 8and has connected to it a pipe 33 to receive the input.

Intermediate vapor components may be taken off of anyone of the plates 1through its valve 9 and a pipe 34 leading to a condenser coil 35.

A tube 36 may be connected to any of the plates 1 and leads to atemperature recorder or indicator 37.

The temperature and the operation of the rectifier may be controlled byautomatically regulating the flow of steam through the kettle and theflow of water through the condenser. The steam regulating mechanism maycomprise a tube 38 connected to a plate 1, a thermostat, 39 and a steamvalve 40 in the pipe 18. The water regulating mechanism 1, a thermostat42, and a valve 43 between a water supply pipe 44 and the connection 26.

The feed may be entered on the receiving side through the manifold 32 toa series of plates 1. A liquid level is maintained within the kettle ata height suflicient to give complete submergence of the tubes 14 in theliquid. This control may be accomplished manually or by afloat control,not shown, but

which may be of a type Well known in the industry. The pressure may becontrolled by vapor removal through the pressure valve 30 or manualvalve 29. Temperatures at the condenser and kettle may be controlled bythe thermostatic apparatus illustrated and tion of a continuous processcolumn, the temperature gradient and the composition gradient aredistorted by the throughput or takeoff of the components; and the actionof the column and the accuracy of separation between individualcomponents is quite diflerent when the column is shut in and no component is being removed, from conditions when there is a throughput. Theaccurate fractionation obtained while a column is shut in is obtained bythe infinite reflux.

By apparatus constructed in accordance with this invention, resultsapproaching in accuracy those inherent in a shut-in column, are obtainedtogether with the advantages inherent in a continuous flow rectifier.

It will be observed that the vertical tubes 4 in reality comprise anumber of vertical columns, nineteen as illustrated, while the plates,including the kettle and the condenser, number thirty. For convenienceof description I may number these columns from left to right; or fromthe receiving side, one to nineteen; and the plates from bottom to top,

one to thirty..

For example, as illustrating the operation of the device, it may beassumed that it is desired to operate the rectifier as a stabilizer fornatural gasoline being fed to plates ten to eighteen, adjacent columnone; and that end products are to be taken off adjacent butane at platetwenty-three, and the residue at plate one, as shown in the drawings. Amolecule of butane introduced adjacent column one on plates ten toeighteen traverses a tortuous course, moving in its liquid phasedownward in any of the several columns and in its vapor phase upward andhorizontal. The construction and operation of the apparatus will be suchas to confine it at column nineteen between the eighteenth andtwentyeighth plate. The molecule will during its tortuous course tend toconfine itself between those plates. At or about the twelfth column theindividual components will be roughly separated. but not with suchaccuracy as to confine the molecule of butane within the selectedplates. Its range of movement between the plates will be progressivelydecreased until it reaches the nineteenth plate where it may be takenoff accurately at the twenty-third plate.

It is to be understood that the foregoing discussion is merelyillustrative of the theory of operation. Butane, a single hydrocarbon,has been selected as an illustration of an intermediate fraction merelyfor simplicity of explanation, but such a cut would ordinarily include agroup of hydrocarbons having a limited boiling range rather than asingle compound. The operation of the apparatus has been describedhypothetically in connec tion with the rectification of naturalgasoline. By comparison, were the apparatus used to distill relativelyheavy oil, for instance, gasoline and the lighter fractions might betaken .93 '1 column nineteen, propane at plate thirty,

ofi as a final end vapor product, kerosene as lea the otherillustration, and the residue would be taken ofi as a final liquidproduct.

It is also to be understood that the number of columns and number ofplates is not limited as specifically illustrated and described, buteither may vary within wide limits depending upon the intended input andthe separations desired.

It will thus be seen that a rectifier has been provided whosetemperature gradient and composition gradient is afiected but little inits final operation by the throughput and whose accuracy approaches thatof a shut-in column. At the same time the apparatus compares'favorablyin cost of construction and operation with less accurate continuousrectifiers.

While the device has been illustrated and described as applicable to thestabilization of petroleum products, its application may be extended toa wide range of uses with accuracy of results and economy inconstruction and operation. I

It is obvious that various changes in construction may be made withinthe scope of the appended claims without departing from the spirit ofthis invention.

I claim:

1. A rectifier including a series of vertical tubes in lateralalignment, a series of superimposed horizontal tubes each of which is incommunication with said vertical tubes, means for maintaining atemperature gradient in said horizontal tubes, a connection forintroducing input into one or more horizontal tubes adjacent a verticaltube, and connections for withdrawing the end products adjacent avertical tube remote from the input.

2. A rectifier including a series of superimposed horizontal tubes, averticaltube adjacent the input connection, a vertical tube adjacent theconnection for removal of the end products and remote from the firstvertical tube, a series of vertical tubes mterposed between and inlateral alignment with the two first mentioned vertical tubes, all ofsaid vertical tubes being in communication with said horizontal tubes,and means for maintaining a temperature gradient in said hori zontaltubes.

3. A rectifier including a series of superimposed horizontal tubes, aseries of vertical tubes in lateral alignment connecting said horizontaltubes, a connection for introducing the input into a set of saidhorizontal tubes, connections for withdrawing the end products adjacenta vertical tube remote from the input connection, and means formaintaining a temperature gradient in said Horizontal tubes.

at. A rectifier including a series of superimposed horizontal tubes, aseries of vertical tubes in lateral alignment, each of said Verticaltubes comprising pipe fittings in verticalalignment and connecting intosaid, liorie zontal tubes, means for introducing. an input, means fortaking ofi the final end product, and means for maintaining atemperature gradient in the horizontal tubes. 1 i

5. A rectifier including a series of super imposed horizontal tubes, aseries of vertical tubes in lateral alignment connecting said.

horizontal tubes, and means for maintaining a temperature gradientincluding a kettle connected to and at thebottom of the vertical tubesand a condenser connected to and at the top of the vertical tubes.

6. A rectifier including a series of superimposed horizontal tubes, aseries of vertical tubes in lateral alignment connecting said horizontaltubes, a kettle having a shell connected to and at the bottom of theVertical tubes, and a heat exchanger within the shell.

7. A rectifier including a series of superimposed horizontal tubes, aseries of, vertical tubes in lateral alignment connecting saidhorizontal tubes, a condenser having a. shell connected to the top ofthe vertical tubes, and a heat exchanger within the shell. V 8. Arectifier including a series of horizontal tubes, a condenser having aheat exchanger, a kettle having a heat exchanger, said horizontal tubes,condenser and kettle being arranged in vertical alignment, a series ofvertical tubes in lateral alignment connecting said horizontal tubes,condenser and kete tle, and automatic means for regulating the flow ofthermal fluids through the heat exchangers of the condenser and kettle.

9. In a rectifier a series of superimposed horizontal tubes arranged toperform the function of plates, each of said tubes having a tight rollof metal lath or its equivalent within the tube.

10. A rectifier having a series of horizontal tubes in verticalalignment, a condenser above the tubes, a kettle below the tubes, aseries of vertical tubes connecting the horizontal tubes, condenser andkettle, a manifold connected to one end of selected horizontal tubes,and connections near the other end vapor component at the condenser andthe final liquid component at the kettle.

11. A rectifier including a series of superimposed horizontal tubularmembers, a series of vertical tubes arranged in lateral alignment andconnecting the horizontal tubes, means for maintaining a temperaturegradient in the horizontal tubes, a connection to introduce the input atone end of the horizontal tubes, and connections to one of thehorizontal tubes at the other end to withdraw an intermediate componentin the vapor phase.

12. A rectifier including a series of superimposed horizontal tubes eachpacked with a roll of metal lath, or its equivalent, to increase thesurface exposure, a heat exchanger above the horizontal tubes, a heatexchanger below the horizontal tubes, a plurality of con- BUY nectionsbetween each set of adjacent tubes and between the heat exchangers andthe tubes adjacent thereto, an input manifold at one end of the tubes,and connections on the end opposite said manifold for Withdrawing theend products. 7

SYDNEY S. SMITH.

